In an interview with Australian news site AFR last week, Rive said Tesla could provide Australia with enough energy storage to combat the energy crisis happening in South Australia.

He specifically said that Tesla’s battery technology could alleviate the problem within 100 days and Musk later confirmed on Twitter that Rive’s comments were indeed true.

This piqued the interest of Mike Cannon-Brookes, the cofounder and co-CEO of enterprise software firm Atlassian. “Lyndon & @elonmusk – how serious are you about this bet? If I can make the $ happen (& politics), can you guarantee the 100MW in 100 days?” he tweeted.

Musk replied: “Tesla will get the system installed and working 100 days from contract signature or it is free. That serious enough for you?”